Oct 3 2006
As part of a rolling investment programme, Aluminium Bahrain has installed an additional heavy-duty overhead crane from UK handling specialist Street Crane Company. Operating in the smelting area, the crane will be used for tapping hot metal from the electrolytic cells, beam raising, floor slab removal and pot shell removal and replacement. The crane is engineered for continuous use in extreme temperatures and in an electrically charged environment with high levels of magnetic flux. It was installed with minimal disruption while the plant kept working.
Street have been working with Aluminium Bahrain since 1992 and now have ten cranes installed on site. The new crane is a double girder construction with a main hoist of 20 tonnes safe working load and two auxiliary hoists, each of eight tonnes. During hot metal decanting, the weight of the crucible is taken by the main hoist with the auxiliaries used for tipping. On-hoist weighing precisely measures the aluminium yield from each cell. Because the crane operates 24 hours a day and has a high proportion of heavy lifts, all lift and travel mechanisms are M8 heavy-duty rating.
For safety, crane travel is regulated by Street Crane’s X-Y Zero load swing prevention system. This optimises crane movement for maximum productivity without load swing. Radio remote operation avoids the restrictions of pendant control and allows the user to position themselves for greatest safety and best visibility. In addition to the main brake on the gearbox first reduction shaft, an additional safety disk brake is fitted to the main crane barrel of the hoist.
The crane uses Street’s VX hoists. The VX twin scrolling open barrel design ensures the hook follows a perfectly vertical path. The open plan design also gives very good access for easy maintenance. Motors and controls have been selected to withstand exposure to high temperature and humidity. Insulation provided at the hook, on the crab frame and between the crab frame and the crane bridge, enables the crane to work safely in a highly charged environment.
Aluminium Bahrain is one of the world’s largest producers of aluminium. The ISO9000 and ISO14001 certified plant produces 830,000 tonnes per annum of 99.9 percent pure aluminium as ingots, billets and rolling slabs for the world market. Expansion has proceeded in phases since the plant first opened in 1971, the latest phase being the development of line five at a cost of 1.7 billion US dollars. Over 2900 people work at the plant, which is a major export earner and contributor to the Bahrain economy. Street Crane’s equipment has been in use on the site for over 10 years, proving to be reliable and efficient, even under heavy use in extreme conditions.